1. Field of the Invention
The subject matter of the present invention pertains to a computer system, and more particularly, to an apparatus within said computer system for suspending a system clock, during execution of an instruction, a predetermined number of clock pulses after an initial error occurs in said system.
2. Description of the Prior Art
In a computer system, during the execution of an instruction, a certain number of clock pulses are generated for the purpose of assisting in the execution of the instruction. If an error occurred during the execution of the instruction, the operation of the computer system could be stopped only when the execution of the instruction was complete. However, a substantial time period elapsed, that is, a substantial number of clock pulses were generated, from the time the initial error occurred to the time when execution of the instruction was complete. As a result of the initial error, and the elapsed time period, other errors were generated within the system.
In the computer systems of the prior art, such as those disclosed in IBM Technical Disclosure Bulletin, Vol. 20, No. 6, November 1977, page 2193, or IBM Technical Disclosure Bulletin, Vol. 22, No. 3, August 1979, page 1169, when the computer system was stopped upon completion of the execution of the instruction, a specific clock pulse was arbitrarily selected and the instruction was re-executed. The computer system would stop when the selected clock pulse was generated during the execution of the instruction. The customer engineer would then attempt to determine the cause of the error, as well as the specific time when the error occurred. However, the other errors, generated as a result of the initial error, still existed in the computer system. If the computer system could have been stopped when the initial error occurred, or at least at some predetermined time prior to the completion of the execution of the instruction, the other errors would not have been generated. In addition, the customer engineer would still have been able to determine the cause of the error, as well as the specific time when the error occurred.